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Completed

NCT Number: NCT05405114

Research Study Investigating How Well NDec Works in People With Sickle Cell Disease

This study examines how well a new, potential medicine called NDec works and is tolerated in people with sickle cell disease. NDec is a combination of two medicines (decitabine-tetrahydrouridine). Both medicines are new for the treatment of sickle cell disease. Participants who are not taking Hydroxyurea (HU) will get NDec, NDec and placebo, or placebo. Participants who are on HU treatment before joining the study will get NDec, NDec and placebo, or continue on HU. Which treatment participants get is decided by chance. Participants getting NDec and/or Placebo will get capsules to take twice weekly. The study will last for about a year.

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Key information

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 2

Primary location

Univ of Alberta Hosp Edmonton, Edmonton, Alberta, Canada

Loading trial locations.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Age above or equal to 18 years at the time of signing informed consent
  • Confirmed diagnosis of SCD (including HbSS, HbSC, HbSβ0 thalassaemia and HbSβ+ thalassaemia or other Sickle Cell disease variants)
  • 2-10 episodes of documented vaso-occlusive crisis (VOCs) within the last 12 months prior to the screening visit
  • Haemoglobin greater than or equal to 5.0 g/dL and below or equal to 10.5 g/dL at visit 1
  • Absolute reticulocyte count above upper limit of the normal (ULN) at visit 1
  • Body weight 40 to 125 kg (inclusive).

Exclusion criteria

  • Patient is on chronic transfusion therapy as defined by receiving scheduled (pre-planned) series of blood transfusion (simple or exchange) for prophylactic purposes, or the patient is likely to begin chronic transfusion therapy during the course of the trial, or has received RBC or whole blood transfusion for any reason within 28 days of visit 1
  • Receipt of erythropoietin or other haematopoietic growth factor treatment within 28 days of signing ICF, or planned treatment with these agents during the trial
  • Receipt of voxelotor, crizanlizumab or L-glutamine treatment within 12 weeks of signing the informed consent form, or planned treatment with such agents during the trial
  • Platelet count greater than 800 x 10^9/L at visit 1
  • Absolute neutrophil count below or equal to 1.5 x 10^9/L at visit 1
  • Any condition/concurrent chronic disease involving the stomach or small intestine which may affect drug absorption, as per investigator's judgement
  • Female who is
  • pregnant, breast-feeding or intends to become pregnant within 6 months after the final trial product administration
  • child-bearing potential and not using highly effective methods of contraception and whose male partner is not using effective contraception, at screening and until 6 months after the last dose of trial product
  • Male with female partner of childbearing potential who does not agree to use condom and whose female partner of childbearing potential is not using a highly effective contraceptive measure from trial start to:
  • Six (6) months after the last dose of trial product for patients on NDec/Placebo
  • Six (6) months after the last dose of trial product for patients outside US and CA randomised to HU
  • Twelve (12) months after the last dose of trial product for patients randomised to HU in US and CA

Treatment and study plan

NDec - oral decitabine-tetrahydrouridine

Drug

Participants will get capsules (oral administration) to take once or twice weekly. The number of capsules will be based on their body weight

HU - Hydroxyurea

Drug

Participants will get capsules daily (oral administration) according to local labelling

Placebo

Drug

Participants will get capsules (oral administration) to take once or twice weekly. The number of capsules will be based on their body weight

Primary outcomes

  1. Change in total haemoglobin

    Time frame: From baseline (week 0) to week 24

    measured in g/dL

Secondary outcomes

  1. Cmax for decitabine from pharmacokinetic assessment

    Time frame: At week 24

    measured in ng/mL

  2. Cmax for tetrahydrouridine from pharmacokinetic assessment

    Time frame: At week 24

    measured in ng/mL

  3. Change in DNA methyltransferase 1 (DNMT1) activity

    Time frame: From baseline (week 0) to week 24

    measured in MFI units

  4. Change in cytidine deaminase (CDA) activity

    Time frame: From baseline (week 0) to week 24

    µmol/L/min

  5. Change in foetal haemoglobin (g/dL)

    Time frame: From baseline (week 0) to week 24

    measured in g/dL

  6. Change in foetal haemoglobin as a proportion of total haemoglobin (%HbF)

    Time frame: From baseline (week 0) to week 24

    measured in %

  7. Change in F-cell level as a proportion of total red blood cell (RBC) (%F-cells)

    Time frame: From baseline (week 0) to week 24

    measured in %

  8. Change in haemolysis measure: absolute reticulocyte count

    Time frame: From baseline (week 0) to week 24

    measured in cells × 10^9/L

  9. Change in haemolysis measure: indirect bilirubin

    Time frame: From baseline (week 0) to week 24

    measured in mg/dL

  10. Change in haemolysis measure: lactate dehydrogenase

    Time frame: From baseline (week 0) to week 24

    measured in U/L

  11. Number of vaso-occlusive crises

    Time frame: From baseline (week 0) to week 48

    number of events

  12. Number of acute chest syndrome

    Time frame: From baseline (week 0) to week 48

    number of events

  13. Number of RBC units transfused

    Time frame: From baseline (week 0) to week 48

    measured in Units

  14. Number of adverse events of grade 3 or higher

    Time frame: From baseline (week 0) to week 52

    number of events

Sponsors and collaborators

Lead sponsor

Novo Nordisk A/S

Industry

Registry information

Official study title

A Multicentre Trial Evaluating the Efficacy and Safety of Oral Decitabine Tetrahydrouridine (NDec) in Patients With Sickle Cell Disease

Acronym: ASCENT1

Important dates

Study start
2022
Primary completion
2025
Study completion
2025
First posted
Jun 6, 2022
Registry last updated
Jul 22, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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